Nutrient timing/meal frequency is highly overstated. If your looking for healthy , calorically dense , convenient between meal snack look to raw nuts.
Id suggest walnuts (for omega 3 content) or almonds.
Others are ok as well , those 2 are my preference.
Good luck.

Note: make sure you hit your daily macros and this addition fits those macros. That most important. Your body will adapt to simple hunger - dont allow it to dictate eating habits. The fact is the desire to eat is very often not a feeling associated with true hunger. Figure out macors , stick to them , monitor progress , adjust accordingly.
Good Luck.